Basic physics lessons teach us that an increase in overall power to bodyweight ratio will drastically improve your vertical jump. This could be further explained in the theory that power is equal to force multiplied by velocity. In simple terms this means that force is the maximum amount of strength that you possess and velocity is how much speed you have. This, however, has to be taken in proportion to your bodyweight, as you cannot be expected to lift twice your bodyweight if you weigh 300 pounds!
Strength exercises for increasing power in your lower body include some well-known bodybuilding moves such as various types of squats and lunges. It is always a good idea to start of with low weights or no weights at all until you get used to the moves and gradually increase accordingly. You should expect to see some improvements within 4-6 weeks and this will be your cue to adding more weight.
Velocity, on the other hand is something which is measured by the speed of the exercise you are performing. Slow movements will increase your strength but will not do much for improvements in speed which is an essential part of the vertical jump. Explosive movements, however, will boost your fast-twitch fibers and your jumping abilities will increase.
You can work on your velocity by adding a few jumping techniques to your training. Again the concept is to use explosive movements rather than slow but a combination of various types of jumps should be incorporated for good measure. These could include box jumps, skipping or simple straight-legged or deep squat jumps.>